I have Windows 7 and Windows Media Player 12 (I think it's the x86 not the x86-64 version but I'm not sure -- how can I be sure?) and I want a way to play FLAC files in it. I want a way to do it which is seamless and reversible. What's the best way to do this?

Also, if you haven't used it yet, I would highly recommend you take a look at VLC Media Player (Also available on Ninite). It allows FLAC audio out the box and you don't have to mess around with any messy codecs!

Currently Windows Media Player and
Media Center don’t include native file
support for a number of lossless audio
codecs including FLAC, OGG, and
basically anything other than
Microsoft’s own WMA files. There is a
cure for this minor omission though so
no worries.

We suggest that 32-bit users download
and install the madFlac decoder from
madshi. For 64-bit users, codecs
for both x64 and x86
versions of windows can be found at
Xiph’s open source site. The files
linked above are the latest versions
available at the time of this post but
you should check Xiph’s page to
check for updated versions.